RE: why doesn't it fit
"This is the OS Max .12CV RC Car/Buggy Engine with the regular crankshaft.
NOT for RC10GT vehicles."
ROFL!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!
Anyways. The engine is a long shaft, the RC10GT uses a short shaft. To make it fit, cut the shaft down and attach the clutch nut.